Creating costumes: Beginner

I have always wanted to make my own armor costumes and I just recently discovered this thing called Pepakura. I can use it to get templates of armors. I am a complete beginner in making costumes(The only costume I ever made was a simple spartan warrior helmet). Obviously the only things I can work with right now are paper and cardboard(materials of that sort) I want to try making a helmet armor piece for practice and I have no Idea where to start. Most of the ones I saw were halo helmets and those things are a little difficult for me right now. I don't know any simple helmet armor designs. Can anyone help me here?

I found this tutorial of sorts, it's at least a starting point. I'm just learning how to make armor myself but I am using worbla and craft foam for everything.